DIY Bone, Prawn & Fish Meal Blend Fertilizer

In December last year, I experimented with making homemade bone meal fertilizer. Today, I’m going to share with you the methods to make bone, prawn (shrimp) and fish meal blend fertilizer. If you have several types of bones and shells, you can make them together and form a blend like what I did. Of course, you can also make them individually. The methods are the same.

DIY homemade bone, prawn (shrimp) and fish meal blend fertilizer. 🦴🍖🍗🌿🌳🌺🌹

First thing first, do you know what are bone, prawn (shrimp) and fish meals? They are meal or powder made by grinding/pounding bones and shells and are used as garden fertilizer in vitalizing our garden. The meal is usually a mix of fine and coarse forms. You can use various types of bones and shells to make meal fertilizer. Some of the common ones are bones from beef, chicken, pork, lamb, mutton, all types of fish, and shells from prawn, shrimp, crab, shellfishes, etc. You’ll collect the bones and shells for a few weeks/months. Then, it’ll take anywhere between 3-7 days to process them into meal.

Before embarking on this DIY project, I’m sure you would like to know whether using a meal from both land and sea animals as garden fertilizer will benefit our soil and plants. Honestly, I don’t know the answer but since bones and shells contain calcium, phosphorous and more, surely it’s an advantage. Moreover, many gardeners and farmers use it as well.

Rather than buying meal fertilizer, why not make your own? Although the making of meal fertilizer spans a few days, the process is easy and you’ll be rewarded with a quality fertilizer (100% meal!) that your garden will love. This sense of accomplishment is wonderful for our soul and besides, you’re saving money as well!

How To Make Bone, Prawn & Fish Meal Blend Fertilizer:

Step 1: Collect the bones and shells
Collect them and store in containers with lids in the freezer until you have a sizeable quantity. It’s better to make a large batch than a few smaller ones because you’ll save time.

For my case, all of the accumulated bones and shells are from kitchen scraps and leftover homemade meals, which is then cook to make bone broth before using it to make meal. I only use bones and shells from the produce that I personally procure. There is a reason for this (refer to step 3. Hint: bone broth). I don’t use the ones from restaurants which I patronize or takeaway from because I’m unsure of their quality. If you know your butchers (reputable ones!) you can request them to give or sell you some.

Step 2: Defrost the bones and shells
When you’re ready to make meal fertilizer, defrost them on the kitchen counter or in the fridge overnight.

I’m usually push to make meal when my freezer is bursting with bones and shells, and I have no space to keep fresh meat. LOL

Step 3: Soften and clean the bones and shells
Next, we need to soften the bones (especially) and shells so that it’ll be very easy to grind them up and therefore will not damage your grinder/food processor. Bones and shells contain remnants of meat and fat, therefore we need to remove them first.

The way to do this is by cooking the bones and shells in water until they are soft, and by the time they are soft, most of the leftover meat and fat would have fallen or easily fallen off the bones. You can do this on the stovetop, slow cooker or instant pot. But then, this way would not reap the benefits of the bones for your consumption. What??

You see, we can make bone broth or also called stock to extract the benefits from the bones and shells such as collagen, vitamins, minerals, enzymes, etc before throwing ’em into the grinder. It’s a win-win situation. Since you’ll be spending the same amount of time ‘cooking’ but in this situation, you are making bone broth which nourishes our gut and inevitability strengthen our immune system, why not make bone broth, right?

I really hope that by encouraging you to make meal fertilizer, I am inadvertently forcing you to make the super nourishing bone broth. This is the reason why I only use bones and shells I buy personally because I get to use better and higher quality ones to make bone broth.

Follow this bone broth (stock) in slow cooker recipe for both slow cooker and stovetop (bring to boil and simmer) cooking for bones. I don’t recommend instant pot. Cook them up to 24 hours or more if the bones are large. Add water especially for stovetop cooking if the water level drop. And test with your fingers whether the bones have softened (it’ll be easy to crush them). After sieving the stock into clean jars, you can make another batch out of it but with a shorter length of time.

For shells, cook them in water (water level just cover the shells) over the stovetop for 1-2 hours. You can make a second batch out of it just like the bones.

After you have harvested the bone broth, you’re left with soft bones and shells. Collect the leftover meat and fat (you can eat it by spicing it up first or feed to your pets) and then rinse the bones and shells. Use the bone broth to make flavorful noodle soup, cook rice in it, etc.

p/s: Sometimes I’m left with no soft bones to make meal because I feed them to the backyard dogs and cats.

Step 4: Dry the soften bones and shells
Dry the now very soft bones and shells so that they can be ground easily into fine sizes. You can achieve this by sun drying, dry in the oven, using a dehydrator or simply air drying it inside/outside the house. Place the bones and shells on a large tray and spread it out. Turn the bones and shells once in a while to ensure all sides are dried evenly. You’ll know it’s dry when you can easily crush them into coarse sizes. It’ll take anywhere from 1-2 days or more to dry them. Be careful when you handle the dried bones and shells because they can be sharp.

Drying bones and shells in a tray.

In my case, I dry them using the sun and oven. For the oven, it’s dried using two ways, by setting the oven at a temperature between 50^oC~100^oC and from the leftover heat (oven is switched off) after baking or roasting.

Step 5: Grind the dried soft bones and shells
Grind the dried soft bones and shells into fine and/or coarse meal. You can use a fine sieve to strain the fine meal and grind the coarser ones again. Several ways to grind the bones and shells are by using mortar and pestle, grinder/mixer, immersion blender, blender, food processor and hand power.

These bones are soft and dried, and are ready to process into meal.

When I DIY-ed the bone meal for the very first time, I used hand power (by crushing with fingers and using a heavy object to pound the bones). It was a bit tedious if I want to make it very fine. This time I tried mortar and pestle and immersion blender. I prefer the latter because even though both methods are messy (bones and shells flying everywhere), I could at least control the messiness a bit with the immersion blender by covering the mouth of the container with a paper/dried cloth. I skip the blender and food processor because I’m lazy to wash the ‘many’ parts. I usually made a mixture of fine and coarse meal with the coarser one towards the end process because I got lazy. But after thinking about it, I thought it’s good to have both fine and coarse meal because the coarser ones will be released into the soil MUCH slower thus ensuring the fertilizing process are longer. Longer fertilizing means nutrients are provided in a longer span of time.

Step 6: Usage & storage:
Once you’ve ground the bones and shells, you can use the homemade meal right away. To use the meal fertilizer, sprinkle the meal around your plants and then water it so that the meal will flow into your soil or mix it with your soil (fresh/current) or finished compost then add to the plants and again, water it. You can add the meal to the soil every few months.

I added the finished meal into my recently finished compost. Then, put it around my plants.

If you have leftover after sprinkling or you want to keep it for later, you can store the meal fertilizer into clean dry containers. That’s it!

I hope you find this how-to guide in making bone, prawn (shrimp), fish meal blend fertilizer useful. Let me know how it goes and please tag me on Instagram/Twitter if you make them!